TY - JOUR
T1 - Nile Red Quantifier
T2 - A novel and quantitative tool to study lipid accumulation in patient-derived circulating monocytes using confocal microscopy
AU - Schnitzler, Johan G.
AU - Moens, Sophie J.Bernelot
AU - Tiessens, Feiko
AU - Bakker, Guido J.
AU - Dallinga-Thie, Geesje M.
AU - Groen, Albert K.
AU - Nieuwdorp, Max
AU - Stroes, Erik S.G.
AU - Kroon, Jeffrey
PY - 2017
Y1 - 2017
N2 - The inflammatory profile of circulating monocytes is an important biomarker for atherosclerotic plaque vulnerability. Recent research revealed that peripheral lipid uptake by monocytes alters their phenotype toward an inflammatory state and this coincides with an increased lipid droplet (LD) content. Determination of lipid content of circulating monocytes is, however, not very well established. Based on Nile Red (NR) neutral LD imaging, using confocal microscopy and computational analysis, we developed NR Quantifier (NRQ), a novel quantification method to assess LD content in monocytes. Circulating monocytes were isolated from blood and used for the NR staining procedure. In monocytes stained with NR, we clearly distinguished, based on 3D imaging, phospholipids and exclusively intracellular neutral lipids. Next, we developed and validated NRQ, a semi-automated quantification program that detects alterations in lipid accumulation. NRQ was able to detect LD alterations after ex vivo exposure of isolated monocytes to freshly isolated LDL in a time-and dose-dependent fashion. Finally, we validated NRQ in patients with familial hypercholesterolemia and obese subjects in pre-and postprandial state. In conclusion, NRQ is a suitable tool to detect even small differences in neutral LD content in circulating monocytes using NR staining.
AB - The inflammatory profile of circulating monocytes is an important biomarker for atherosclerotic plaque vulnerability. Recent research revealed that peripheral lipid uptake by monocytes alters their phenotype toward an inflammatory state and this coincides with an increased lipid droplet (LD) content. Determination of lipid content of circulating monocytes is, however, not very well established. Based on Nile Red (NR) neutral LD imaging, using confocal microscopy and computational analysis, we developed NR Quantifier (NRQ), a novel quantification method to assess LD content in monocytes. Circulating monocytes were isolated from blood and used for the NR staining procedure. In monocytes stained with NR, we clearly distinguished, based on 3D imaging, phospholipids and exclusively intracellular neutral lipids. Next, we developed and validated NRQ, a semi-automated quantification program that detects alterations in lipid accumulation. NRQ was able to detect LD alterations after ex vivo exposure of isolated monocytes to freshly isolated LDL in a time-and dose-dependent fashion. Finally, we validated NRQ in patients with familial hypercholesterolemia and obese subjects in pre-and postprandial state. In conclusion, NRQ is a suitable tool to detect even small differences in neutral LD content in circulating monocytes using NR staining.
UR - http://www.scopus.com/inward/record.url?scp=85033559207&partnerID=8YFLogxK
U2 - https://doi.org/10.1194/jlr.D073197
DO - https://doi.org/10.1194/jlr.D073197
M3 - Article
C2 - 28972117
SN - 0022-2275
VL - 58
SP - 2210
EP - 2219
JO - Journal of Lipid Research
JF - Journal of Lipid Research
IS - 11
ER -